What Georgia county will have the most people in 2040? (Hint: not Fulton)

That’s how many people the Atlanta Regional Commission expects to live in Gwinnett in 2040, a number that would make the county Georgia’s most populous – far more populous than Cobb and DeKalb, and bigger than Fulton for the first time ever. The number would mark a growth of about 57 percent (or nearly 500,000 people) for Gwinnett, nearly doubling Fulton’s expected increase of about 30 percent (or 294,086 new residents).

Fulton County’s projected 2040 population is 1,264,376.

ARC researcher Mike Carnathan said the projections are based on national forecasts that use "a respected and oft-used econometric model" -- one based on things like jobs, birth rates, migration and other demographic factors. The ARC's interactive dashboard -- the full version of which can be found here -- has population projections for 20 counties in the greater metro Atlanta region.

Some highlights:

*Forsyth County is actually expected to grow the most, percentage-wise, by 2040, more than doubling its population to just over 430,000.

*Cobb, DeKalb and Clayton are expected to have the 20-county region’s least growth, percentage-wise, at 22, 22 and 23 percent, respectively. Cobb will have a population of about 885,000 residents in 2040, the ARC projects, and DeKalb will land around 874,000. Clayton is expected to have a population around 327,000.